fix scrolling bug when deleting all characters on a line
fix scrolling bug when deleting all characters on a line

cjwirth/RichEditorView,cjwirth/RichEditorView,jesiegel1/RichEditorView,jesiegel1/RichEditorView,cjwirth/RichEditorView,Estanque/RichEditorView,Estanque/RichEditorView,Estanque/RichEditorView,jesiegel1/RichEditorView,jesiegel1/RichEditorView,cjwirth/RichEditorView,Estanque/RichEditorView,Estanque/RichEditorView,jesiegel1/RichEditorView